Old, obsolete and costly construction processes for buildings based on a concrete foundation upon which stands a structure formed by columns and beams, enclosed at the top by a slab and laterally by bricks and other similar construction materials, are increasingly being replaced with pre-fabricated modules, usually made of reinforced concrete, which form prismatic-rectangular blocks with respective openings for doors, windows, etc., so that each module consists of reinforced concrete panels corresponding to each of its sides, factory-made, installable on the ground, specifically over an appropriate foundation, joined together at their edges usually with the help of mechanical means, such as screws, nuts or other things.
This multiple-part construction of the modules, as well as their attachment to the foundation, is inherently prone to expansion and vibrations, whereby cracks and humidity frequently appear on the modules.
Furthermore, this structuring does not preclude the need for subsequent coatings both internally and externally, as well as chamber formation for the passage of service ducts and for the introduction or spreading of insulation materials correspondingly to external wall surfaces.
In an attempt to overcome these problems, there are some known solutions wherein two, three, four or five sides of the prismatic block are joined together at their origin as a single piece, i.e. reducing the number of pieces forming the module and consequently the number of joints put between them.
This is the case with the invention patent EP0650812, in which the process for obtaining a module for construction is described. This includes a construction phase in the factory of an internal permanent formwork based on at least six constituent elements, consisting of a bottom base, a top base and four lateral walls, after which, the mounting of the integral elements of the said permanent formwork is carried out. This involves configuring a rectangular prismatic block, supporting the said rectangular prismatic block directly on the ground or on a horizontal platform, and subsequently adding an external formwork to the formwork described above, proceeding thereafter to fill the perimetral space existing between the two formworks with highly-fluid self-compacting concrete, so that in this last phase, after having the concrete has hardened, the external and recoverable formwork is removed, thereby achieving the module.
With this solution, the first problem described is partially solved while the second remains completely unresolved.
The inventor is not aware of the existence of any other solutions in industry or on the site of construction to achieve a completely monolithic state, i.e. where all six sides of the prismatic block are joined together as a single piece to provide the benefits listed above.
Description of the Invention
The manufacturing process of compact modules for use in construction proposed by the invention achieves this complete monolithic state, as mentioned above, as well as much lower manufacturing costs in comparison with any of the conventional construction systems.
More specifically, to achieve this, the process begins with a factory-made permanent formwork, which integrates all the lateral sides as well as the upper and lower slabs, corresponding to the inside of the desired prismatic cubicle space. This permanent formwork integrates both the cubicle's internal finishing materials and the appropriate hollows for doors, windows, etc., as well as orthogonal partitioning walls corresponding to these hollows, and with a width consistent with the thickness for the internal or external wall as a whole.
Once these are hardened, the dimensions of which are restricted only by logical transportation limits, the formworks are stored within the factory itself, or where deemed most appropriate, until the time for their use.
At that time, the geometry of the module to be built is traced on the floor over a plated smooth simple platform, which may even be a properly compacted floor. This can be done in the factory or on the building-site.
The lower slab is provided on top of this platform in the appropriate position, with the assistance of supports that sufficiently separate the slab from the platform, according to the forecast total thickness of the lower slab.
We then proceed to provide the necessary walls comprising each module, which could simply consist of the perimetral walls, or one or several of the internal compartment partition walls, thus also holding on to the lower slab by means of high strength putty, and finally proceeding to place the upper slab.
Furthermore, all necessary installations are placed on the external side of this internal integral formwork, such as electricity, telephone, sanitation, drinking water, etc.
Subsequently and above these installations, i.e. externally to them, insulation is either placed or spread over those wall surfaces that require it.
Next, a surrounding reinforcement is provided, which affects all six sides of the formwork and is calculated according to the required strength.
Next, an external formwork is put in place. This is made of four lateral pieces, each substantially protruding over the adjacent piece at one of its edges, so that this external formwork can allow for slabs and walls of any size, by simply joining together the four overlapping lateral sides.
At the next operational phase, we proceed to fill the space between internal permanent formwork and the external recoverable formwork, with highly-fluid self-compacting concrete of high initial and final strengths, to prevent segregation at the pouring stage and thereby obtaining a 100% monolithic state, the concrete pouring achieving the highest forecast level for the upper slab, i.e. a hollow rectangular prismatic block is obtained, made of reinforced concrete and a single-piece structure, whereby the module does not require rigid floor fixing and prevents any risk of vibration or expansion that could cause the appearance of cracks and humidity within the module.
After stripping the module, i.e. after removal of the external and recoverable formwork, the structural behaviour of the module is identical to that of a beam, providing sufficient stability and strength for use at one level, or for piling in stacks of ten, twelve, or even more, depending on the thickness of its walls, by joining together the modules with the corresponding anchors for both vertical and horizontal handling.
All of this, in unison, achieves not only excellent quality, but also a much lower manufacturing cost than previously conceived, owing to the system's simplicity, while providing very high versatility for any industry, whether through automation or simply by mechanisation, being affordable for all investors, regardless of their location or financial ability, and with the consequent development of industrial production of decent, safe and affordable housing for any given situation, besides remaining open to a plethora of possibilities with respect to quality, given its adaptation to different finishes of and installations to the internal and permanent formwork.